Revit uses a process similar to printing to export CAD files.
You can export a single sheet, or export multiple sheets.
EXPORT SINGLE SHEET
First open the sheet you want to export. (Refer FINDING A SHEET (DRAWING).
Click on the purple R in top left corner, select Export > CAD formats > DWG (or DGN).
The Export CAD dialog box will appear.
Make sure Export: is <current view/sheet only>
Then hit Next...
The Export CAD Formats dialog box opens.
Browse to the folder to save the CAD file to.
Edit the File Name.
Untick Export views on sheets and links as external references.
Hit OK and CAD file will be created.
If you haven't made any changes then QUIT WITHOUT SAVING.
If you have made changes you want to keep then SAVE & CLOSE.
EXPORT MULTIPLE SHEETS
Click on the purple R in top left corner, select Export > CAD formats > DWG (or DGN).
The Export CAD dialog box will appear.
Open the sure Export: list and either select a pre-existing sheet set or <in-session view/sheet set>
Then hit Next...
A list of sheets appears, containing either the sheets in the sheet set or all sheets and views in the project file.
If you selected <in-session view/sheet set> you can use Show in list to restrict list to Sheets only:
Tick or untick to get a list of the sheets you want to export, then hit Next...
The Export CAD Formats dialog box opens.
Browse to the folder to save the CAD file to.
Edit the File Name prefix (Revit will add drawing number for each sheet).
Make sure Naming is Automatic - Long (Specify prefix)
Untick Export views on sheets and links as external references.
Hit OK and CAD files will be created.
If you haven't made any changes then QUIT WITHOUT SAVING.
If you have made changes you want to keep then SAVE & CLOSE.